1. Field of the Invention:
The present invention relates to a device for adjusting or regulating an image density reproduced in a composite information copying apparatus imparted with a function for recording in a composite manner electric information signals available from external sources together with an image of an original to be copied.
2. Description of the Prior Art
The composite information recording apparatus of the above type comprises generally an optical system 3 for projecting an image of an original resting on a copy board 1 to a drum 2 having a photoconductive or light sensitive surface layer such as of Se, CdS thereon, a reproducing device 4 for reproducing electric information signals on the light sensitive drum 2 as an electrostatic latent image, and a developing device 5 such as a magnetic brush developing device for visualizing and recording the electrostatic latent image on the light sensitive drum 2 by using toner as per se well known in the field. With copying apparatus of such arrangement, it is possible to record the image of an original or electric information signals from the reproducing device, respectively, or alternatively a combination of the image of the original and the electric information signal in a composite matter in which a part of the recorded information is derived through the optical system, while the other part is derived from the reproducing device.
For preparing a sheet or a page of data containing image information from the original and the electric information signal from the external source in a composite manner in the composite information recording apparatus, there may arise the possibility that non-uniformity in the image density distribution will occur, if the light intensity of the image optically projected onto the drum surface and the intensity of the light beam flux output from the reproducing device (such as an optical fiber tube) are not balanced with each other.